1. Field of the Invention
The present invention relates to a control method for a refrigerator, and more particularly to a control method for a refrigerator, in which cold air is blown to an ice-making unit regardless of a load of a freezing compartment when quick ice-making instructions are inputted to the refrigerator.
2. Description of the Related Art
Generally, a refrigerator is an apparatus in which food (hereinafter, referred to as “objects”) is stored in a fresh state by a freezing cycle, and is provided with a freezing compartment for storing objects at a sub-zero temperature, a refrigerating compartment for storing objects at an above-zero temperature, and an ice-making unit installed in the freezing compartment for making ice from water using cold air.
FIG. 1 is a block diagram of a conventional refrigerator, illustrating a freezing cycle.
As shown in FIG. 1, the conventional refrigerator comprises a compressor 2 for compressing a refrigerant into a high-temperature and high-pressure gaseous state, a condenser 4 for condensing the refrigerant compressed by the compressor 2 by emitting heat of the refrigerant to its circumferential air, an expansion unit 6 for decompressing the refrigerant condensed by the condenser 4, an evaporator 8 for evaporating the refrigerant decompressed by the expansion unit 6 by absorbing heat of the circumferential air, a cooling fan 10 for forcibly convecting air cooled by the evaporator 8 to a freezing or refrigerating compartment, a load sensor 12 for sensing a load of the freezing compartment, and a control unit 14 for turning on or off the compressor 3 and the cooling fan 10 by comparing an obtained value sensed by the load sensor 12 to a predetermined temperature.
FIG. 2 is a schematic front view showing the inner structure of the conventional refrigerator. FIG. 3 is a perspective view of the conventional refrigerator, illustrating the condition in which freezing and refrigerating compartments are in an opened state.
As shown in FIGS. 2 and 3, the conventional refrigerator includes a refrigerator body in which a freezing compartment F and a refrigerating compartment R are arranged close to each other, and defined by a barrier 2 located at opposite sides of the freezing compartment F and the refrigerating compartment R. A freezing compartment door 4 is hingably mounted to the refrigerator body in front of the freezing compartment F such that the freezing compartment 4 is opened or closed by the freezing compartment door 4. A refrigerating compartment door 6 is also hingably mounted to the refrigerator body in front of the refrigerating compartment R such that the refrigerating compartment is opened or closed by the refrigerating compartment door 6.
The freezing compartment F is provided, at the lower portion of the rear wall thereof, with cold air return holes 28 adapted to return the cold air, used to cool the freezing compartment F to a desired freezing temperature, to the circumference of the evaporator 8. The freezing compartment F is also provided, at the upper portion of a rear wall thereof, with cold air discharge holes 27 adapted to discharge the air cooled by the evaporator 8, that is, cold air, into the freezing compartment F.
An ice-making machine 41 for making ice from water and an ice back 42 for containing the ice made by the ice-making machine 41 are installed at the upper portion of the freezing compartment F in front of the uppermost cold air discharge holes 27.
A dispenser 43 for pulling out ice therethrough and an ice chute 44 for guiding ice contained in the ice bank 42 to fall into the dispenser 43 are installed at the rear surface of the freezing compartment door 4.
The barrier 2 is provided, at its upper portion, with a cold air discharge duct 29 for discharging the cold air into the refrigerating compartment R, and at its lower portion, with a cold air return duct 30 for circulating the cold air in the refrigerating compartment R.
A plurality of shelves 31 are located in the freezing compartment F and the refrigerating compartment R such that they are vertically spaced apart from one another, and a plurality of baskets 32 adapted to receive food or containers are mounted to the back surfaces of the freezing compartment door 4 and the refrigerating compartment door 6 such that they are vertically spaced apart from one another.
Now, a control method for the conventional refrigerator having the above mentioned configuration will be described.
FIG. 4 is a block diagram illustrating a control method for the conventional refrigerator.
First, the load sensor 12 senses the temperature of the freezing compartment F, and then outputs a signal corresponding to the sensed temperature to the control unit 14. The control unit 14 compares the temperature of the freezing compartment F sensed by the load sensor 12 to predetermined maximum and minimum temperatures (S1 and S2).
In case that it is determined that the temperature of the freezing compartment F sensed by the load sensor 12 is higher than the predetermined maximum temperature, the control unit 14 turns on the compressor 2 and the cooling fan 10 (S3).
A refrigerant in a low-temperature and low-pressure state flows in the evaporator 8 by the operation of the compressor 2, and air at the circumference of the evaporator 8 passes through the surface of the evaporator 8 and is heat-exchanged with the refrigerant in the low-temperature state, thus having a low temperature. The cold air having the low temperature at the circumference of the evaporator 8 is discharged into the freezing compartment F or the refrigerating compartment R by the operation of the cooling fan 10.
As shown in FIGS. 2 and 3, the cold air is discharged into the freezing compartment F through the cold air discharge holes 27, and moves to the lower portion of the freezing compartment F, thus cooling objects in the freezing compartment F. Then, the cold air is circulated toward the evaporator 12 through the cold air return holes 28.
The cold air, which is discharged into the upper portion of the freezing compartment F through the uppermost cold air discharge holes 27, passes through the ice-making machine 41, thus making ice from water supplied to the ice-making unit 41. Then, the cold air moves to the lower portion of the freezing compartment F.
The ice made by the ice-making unit 41 is transferred to the ice bank 42 and is contained in the ice bank 42. When a user manipulates a control panel or an ice pulling lever, the ice falls into the dispenser 44 through the ice chute 43.
As shown in FIG. 2, the cold air is discharged into the upper portion of the refrigerating compartment R through the cold air discharge duct 29, and moves to the lower portion of the refrigerating compartment R, thus cooling objects in the refrigerating compartment R. Then, the cold air is circulated toward the evaporator 12 through the cold air return duct 30.
In case that it is determined that the temperature of the freezing compartment F sensed by the load sensor 12 is lower than the predetermined minimum temperature, the control unit 14 turns off the compressor 2 and the cooling fan 10 (S4).
Thereafter, the control unit 14 controls the turning on/off of the compressor 2 and the cooling fan 10 according to variation in load (i.e., sensed temperature) of the freezing compartment F.
However, since the compressor 2 for cooling the air of the freezing compartment F and the cooling fan 10 for blowing the air of the freezing compartment F are turned on/off according to the load of the freezing compartment F, the above mentioned control method of the conventional refrigerator has a limitation in rapidly coping with the requirements of users, who want to perform a quick ice-making mode of the ice-making unit.